CHAPTER 15: Unit 5. Application: Significance of Chirality in the biological world

Application: Significance of Chirality in the biological world

Importance of Chirality: In the human body, chiral forms of a molecule usually exhibit different responses and our bodies can normally use only one form. Sometimes both forms are biologically active. All proteins, fats and carbohydrates are made of chiral molecules.

The case of Thalidomide:

Thalidomide was synthesized in West Germany in 1953 by Chemie Grünenthal. It was marketed (available to patients) from October 1, 1957 (West Germany) into the early 1960’s. Sold in at least 46 countries (US not included), Thalidomide was hailed as a “wonder drug” that provided a “safe, sound sleep”. It was a sedative that was found to be effective when given to pregnant women to combat many of the symptoms associated with morning sickness. No clinicaltesting was available to show that Thalidomide molecules could cross the placental wall affecting the fetus until it was too late

Here is one video on application of chirality in biological world

Conclusion:

• Some organic molecules possess one or more (n) stereocenters, thus several (2n) stereoisomers are possible.
• Enantiomers and diastereomers differ only in the position of atoms in space.
• Unlike Diastereomers, Enantiomers display the same chemical/physical properties in an achiral environment.
• In the human body (chiral environment) two enantiomers can be discriminated producing different biological